F04DNON-POSITIVE-DISPLACEMENT PUMPS engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02This subclass covers non-positive-displacement pumps for liquids, for elastic fluids, or for liquids and elastic fluids whether rotary or not having pure rotation.This subclass does not cover combinations of non-positive-displacement pumps with other pumps, which are covered by subclass F04B, except that the use of such other pumps for priming or boosting non-positive-displacement is covered by this subclass.Attention is drawn to the Notes preceding class F01, especially as regards the definition of "pump".In this subclass non-limiting references (in the sense of paragraph 39 of the Guide to the IPC) may still be displayed in the scheme. F04D1/00Pumping liquids, or liquids and elastic fluids, by rotary pumps pumping liquids and elastic fluids at the same time F04D31/00 F04D1/00Radial-flow pumps, e.g. centrifugal pumpsHelico-centrifugal pumps adapted for pumping specific fluids F04D7/00; priming or boosting F04D9/00 F04D1/003Having contrarotating parts F04D1/006double suction pumps F04D1/02having non-centrifugal stages, e.g. centripetal F04D1/025Comprising axial and radial stages F04D1/04Helico-centrifugal pumps F04D1/06Multi-stage pumps F04D1/02, F04D13/10 take precedence F04D1/063of the vertically split casing type F04D1/066the casing consisting of a plurality of annuli bolted together F04D1/08the stages being situated concentrically F04D1/10with means for changing the flow-path through the stages, e.g. series-parallel, e.g. side loads F04D1/12Pumps with scoops or like paring members protruding in the fluid circulating in a bowl F04D1/14Pumps raising fluids by centrifugal force within a conical rotary bowl with vertical axis F04D3/00Axial-flow pumps priming or boosting F04D9/00 F04D3/005with a conventional single stage rotor F04D3/02of screw type F04D5/00Pumps with circumferential or transverse flow control thereof F04D15/005 F04D5/001Shear force pumps F04D5/002Regenerative pumps for elastic fluids F04D23/008 F04D5/003of multistage type F04D5/005the stages being radially offset F04D5/006the stages being axially offset F04D5/007Details of the inlet or outlet F04D5/008Details of the stator, e.g. channel shape F04D7/00Pumps adapted for handling specific fluids, e.g. by selection of specific materials for pumps or pump parts F04D11/005, F04D29/22 take precedence F04D7/02of centrifugal type F04D7/04the fluids being viscous or non-homogenous F04D7/045with means for comminuting, mixing stirring or otherwise treating F04D7/06the fluids being hot or corrosive, e.g. liquid metals F04D7/065for liquid metal F04D7/08the fluids being radioactive F04D9/00PrimingPreventing vapour lock F04D9/001Preventing vapour lock F04D9/041 takes precedence F04D9/002by means in the very pump F04D9/041 takes precedence F04D9/003separating and removing the vapour F04D9/004Priming of not self-priming pumps F04D9/005by adducting or recycling liquid F04D9/006 takes precedence F04D9/006by venting gas or using gas valves F04D9/007Preventing loss of prime, siphon breakers stopping of pumps F04D15/02 F04D9/008by means in the suction mouth, e.g. foot valves F04D9/02Self-priming pumps F04D9/04using priming pumpsusing booster pumps to prevent vapour-lock F04D9/041the priming pump having evacuating action F04D9/043 and F04D9/06 take precedence F04D9/042and means for rendering its in operative F04D9/043the priming pump being hand operated or of the reciprocating type F04D9/044Means for rendering the priming pump inoperative F04D9/045the means being liquid level sensors F04D9/046the means being floats F04D9/047the means being flow sensors F04D9/048the means being outlet pressure sensors F04D9/049by operator interventions F04D9/06of jet type F04D9/065the driving fluid being a gas or vapour, e.g. exhaust of a combustion engine F04D11/00Other rotary non-positive-displacement pumps pumping installations or systems F04D13/00 F04D11/005Swash-type impeller pumps F04D13/00Pumping installations or systems controlling F04D15/00 F04D13/02Units comprising pumps and their driving means predominant aspects of the driving means, see the relevant classes for such means F04D13/021containing a coupling F04D13/022a coupling allowing slip, e.g. torque converter F04D13/023for reducing start torque F04D13/024a magnetic coupling F04D13/025Details of the can separating the pump and drive area F04D13/026Details of the bearings F04D13/027Details of the magnetic circuit F04D13/028the driving means being a planetary gear F04D13/04the pump being fluid driven F04D13/043the pump wheel carrying the fluid driving means F04D13/046the fluid driving means being a hydraulic motor of the positive displacement type F04D13/06the pump being electrically driven F04D13/0606Canned motor pumps F04D13/0613Special connection between the rotor compartments F04D13/062pressure compensation between motor- and pump- compartment F04D13/0626Details of the can F04D13/0633Details of the bearings F04D13/064Details of the magnetic circuit F04D13/0646the hollow pump or motor shaft being the conduit for the working fluid F04D13/0653the motor being flooded F04D13/066Floating-units F04D13/0666the motor being of the plane gap type F04D13/0673the motor being of the inside-out type F04D13/068Battery powered F04D13/0686Mechanical details of the pump control unit pump control F04D15/00 F04D13/0693Details or arrangements of the wiring F04D13/08for submerged use F04D13/083and protected by a gas-bell F04D13/086the pump and drive motor are both submerged F04D13/10adapted for use in mining bore holes F04D13/12Combinations of two or more pumps combinations with priming pumps or booster pumps to counteract vapour-lock F04D9/04 F04D13/14the pumps being all of centrifugal type deviation valves F04D15/0016 F04D13/16with storage reservoirs F04D15/00Control, e.g. regulation, of pumps, pumping installations or systems F04D15/0005by using valves F04D15/0011by-pass valves F04D15/0016mixing-reversing- or deviation valves F04D15/0022throttling valves or valves varying the pump inlet opening or the outlet opening F04D15/0027Varying behaviour or the very pump F04D15/0055 and F04D29/46 take precedence F04D15/0033By-passing by increasing clearance between impeller and its casing F04D15/0038by varying the effective cross-sectional area of flow through the rotor F04D15/0044by introducing a gas F04D15/005the pumps being of the circumferential flow type F04D15/0055Rotors with adjustable blades F04D15/0061responsive to temperature F04D15/0066by changing the speed, e.g. of the driving engine F04D15/0072Installation or systems with two or more pumps, wherein the flow path through the stages can be changed, e.g. series-parallel F04D15/0077Safety measures F04D15/02 takes precedence F04D15/0083Protection against sudden pressure change, e.g. check valves F04D15/0088Testing machines F04D15/0094Indicators of rotational movement F04D15/02Stopping of pumps, or operating valves, on occurrence of unwanted conditions F04D15/0209responsive to a condition of the working fluid F04D15/029 takes precedence F04D15/0218the condition being a liquid level or a lack of liquid supply F04D15/0227Lack of liquid level being detected using a flow transducer F04D15/0236Lack of liquid level being detected by analysing the parameters of the electric drive, e.g. current or power consumption F04D15/0245responsive to a condition of the pump F04D15/0254the condition being speed or load F04D15/0263the condition being temperature, ingress of humidity or leakage F04D15/0272the condition being wear or a position F04D15/0281responsive to a condition not otherwise provided for F04D15/029for pumps operating in parallel F04D17/00Pumping elastic fluids by rotary pumps F04D17/00Radial-flow pumps, e.g. centrifugal pumpsHelico-centrifugal pumps F04D21/00 takes precedence F04D17/02having non-centrifugal stages, e.g. centripetal F04D17/025comprising axial flow and radial flow stages F04D17/04of transverse-flow type F04D17/06Helico-centrifugal pumps F04D17/08Centrifugal pumps F04D17/10for compressing or evacuating F04D17/105with double suction F04D17/12Multi-stage pumps F04D17/122the individual rotor discs being, one for each stage, on a common shaft and axially spaced, e.g. conventional centrifugal multi- stage compressors F04D17/125the casing being vertically split F04D17/127with radially spaced stages, e.g. for contrarotating type F04D17/14with means for changing the flow-path through the stages, e.g. series-parallel, e.g. side-loads, surge control F04D27/02 F04D17/16for displacing without appreciable compression F04D17/161Shear force pumps F04D17/162Double suction pumps F04D17/164Multi-stage fans, e.g. for vacuum cleaners F04D17/165Axial entry and discharge F04D17/167Operating by means of fibrous or porous elements suction filters F04D29/701, e.g. with sponge rotors F04D17/168Pumps specially adapted to produce a vacuum F04D17/18characterised by use of centrifugal force of liquids entrained in pumps , e.g. by means of an auxiliary liquid; fluid ring compressors F04C19/00 F04D19/00Axial-flow pumps F04D21/00 takes precedence; pump comprising axial flow and radial flow stages F04D17/025 F04D19/002Axial flow fans F04D19/005reversible fans F04D19/007multistage fans F04D19/02Multi-stage pumps F04D19/022with concentric rows of vanes; F04D19/024with contrarotating parts F04D19/026with a plurality of shafts rotating at different speeds F04D19/022 takes precedence F04D19/028Layout of fluid flow through the stages F04D19/04specially adapted to the production of a high vacuum, e.g. molecular pumps F04D19/042Turbomolecular vacuum pumps F04D19/044Holweck-type pumps F04D19/046Combinations of two or more different types of pumps F04D19/048comprising magnetic bearings F04D21/00Pump involving supersonic speed of pumped fluids F04D23/00Other rotary non-positive-displacement pumps pumping installations or systems F04D25/00 F04D23/001Pumps adapted for conveying materials or for handling specific elastic fluids F04D23/003of radial-flow type F04D23/005of axial-flow type F04D23/006Creating a pulsating flow F04D23/008Regenerative pumps for liquids or for liquids and elastic fluids F04D5/002 F04D25/00Pumping installations or systems controlling F04D27/00 F04D25/02Units comprising pumps and their driving means predominant aspect of the driving means, see the relevant classes for such means F04D25/022comprising a yielding coupling, e.g. hydraulic a magnetic coupling F04D25/026 F04D25/024the driving means being assisted by a power recovery turbine F04D25/026with a magnetic coupling F04D25/028the driving means being a planetary gear F04D25/04the pump being fluid-driven pumps driven by exhaust gases F02B37/00, F02B39/00; turbochargers F02C6/12 F04D25/045the pump wheel carrying the fluid driving means, e.g. turbine blades F04D25/06the pump being electrically driven F04D25/08 takes precedence F04D25/0606the electric motor being specially adapted for integration in the pump F04D25/0613the electric motor being of the inside-out type, i.e. the rotor is arranged radially outside a central stator F04D25/062Details of the bearings F04D25/0626Details of the lubrication F04D25/0633Details of the magnetic circuit F04D25/064Details of the rotor F04D25/0646Details of the stator F04D25/0653the motor having a plane air gap, e.g. disc-type F04D25/066Linear Motors F04D25/0666a sensor is integrated into the pump/motor design F04D25/0673Battery powered F04D25/068Mechanical details of the pump control unit pump control details F04D27/00 F04D25/0686specially adapted for submerged use F04D25/0693Details or arrangements of the wiring F04D25/08the working fluid being air, e.g. for ventilation F04D25/082the unit having provision for cooling the motor F04D25/084hand fans F04D25/086hand operated F04D25/088Ceiling fans F04D25/10the unit having provisions for automatically changing direction of output air F04D25/105by changing rotor axis direction, e.g. oscillating fans interconnecting rotary motion and oscillating motion F16H F04D25/12the unit being adapted for mounting in apertures F04D25/14and having shutters, e.g. automatically closed when not in use F04D25/16Combinations of two or more pumps Producing two or more separate gas flows F04D25/163driven by a common gearing arrangement F04D25/166using fans F04D27/00Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids F04D27/001Testing thereof; Determination or simulation of flow characteristics; Stall or surge detection, e.g. condition monitoring F04D27/002by varying geometry within the pumps, e.g. by adjusting vanes F04D27/003by throttling F04D27/002 takes precedence F04D27/004by varying driving speed F04D27/005by changing flow path between different stages or between a plurality of compressors; Load distribution between compressors F04D27/006by influencing fluid temperatures F04D27/007Conjoint control of two or more different functions F04D27/008Stop safety or alarm devices, e.g. stop-and-go control; Disposition of check-valves F04D27/009by bleeding, by passing or recycling fluid F04D27/02Surge control surge detection F04D27/001 F04D27/0207by bleeding, bypassing or recycling fluids influencing the boundary layer by an uncontrolled bleeding of the working fluid F04D29/681 F04D27/0215Arrangements therefor, e.g. bleed or by-pass valves F04D27/0223Control schemes therefor F04D27/023Details or means for fluid extraction F04D27/0238Details or means for fluid reinjection F04D27/0246by varying geometry within the pumps, e.g. by adjusting vanes F04D27/0253by throttling F04D27/0246 takes precedence F04D27/0261by varying driving speed F04D27/0269by changing flow path between different stages or between a plurality of compressors; load distribution between compressors F04D27/0276by influencing fluid temperature F04D27/0284Conjoint control of two or more different functions F04D27/0292Stop safety or alarm devices, e.g. stop-and-go control; Disposition of check-valves F04D29/00Details, component parts, or accessories machine elements in general F16 F04D29/002especially adapted for elastic fluid pumps F04D29/005Decorative aspects, i.e. features which have no effect on the functioning of the pump F04D29/007especially adapted for liquid pumps F04D29/02Selection of particular materials for handling specific liquids F04D7/00 F04D23/001 F04D29/023especially adapted for elastic fluid pumps F04D29/026especially adapted for liquid pumps F04D29/04Shafts or bearings, or assemblies thereof specially adapted for elastic fluid pumps F04D29/05 F04D29/0405joining shafts, e.g. rigid couplings, quill shaftsThe group F04D29/0405 is no longer used for the classification of new documents as from July 1st, 2007. The backlog of this group is being continuously reclassified to F04D29/044 and F04D29/054 F04D29/041Axial thrust balancing F04D29/0413hydrostatic; hydrodynamic thrust bearings F04D29/0416balancing pistons F04D29/042Axially shiftable rotors F04D29/041 takes precedence ; control by creating a by-pass F04D15/0027 F04D29/043Shafts F04D29/044Arrangements for joining or assembling shafts F04D29/046Bearings F04D29/0462Bearing cartridges F04D29/0465Ceramic bearing designs F04D29/0467Spherical bearings F04D29/047hydrostatichydrodynamic F04D29/0473for radial pumps F04D29/0476for axial pumps F04D29/048magneticelectromagnetic F04D29/049Roller bearings F04D29/05Shafts or bearings, or assemblies thereof, specially adapted for elastic fluid pumps F04D29/051Axial thrust balancing F04D29/0513hydrostatic; hydrodynamic thrust bearings F04D29/0516balancing pistons F04D29/052Axially shiftable rotors F04D29/051 takes precedence ; control by creating a by-pass F04D27/0246 F04D29/053Shafts F04D29/054Arrangements for joining or assembling shafts F04D29/056Bearings F04D29/0563Bearings cartridges F04D29/0566Ceramic bearing designs F04D29/057hydrostatichydrodynamic F04D29/058magneticelectromagnetic F04D29/059Roller bearings F04D29/06Lubrication F04D13/0606, F04D13/0646, F04D13/0653 take precedence F04D29/061especially adapted for liquid pumps F04D29/063specially adapted for elastic fluid pumps F04D29/08Sealings F04D29/083especially adapted for elastic fluid pumps F04D29/086especially adapted for liquid pumps F04D29/10Shaft sealings F04D29/102especially adapted for elastic fluid pumps F04D29/104the sealing fluid being other than the working fluid or being the working fluid treated F04D29/106especially adapted for liquid pumps F04D29/108the sealing fluid being other than the working liquid or being the working liquid treated F04D29/12using sealing-rings F04D29/122especially adapted for elastic fluid pumps F04D29/124with special means for adducting cooling or sealing fluid F04D29/126especially adapted for liquid pumps F04D29/128with special means for adducting cooling or sealing fluid F04D29/14operative only when pump is inoperative F04D29/143especially adapted for elastic fluid pumps F04D29/146especially adapted for liquid pumps F04D29/16between pressure and suction sides F04D29/161especially adapted for elastic fluid pumps F04D29/162of a centrifugal flow wheel F04D29/164of an axial flow wheel F04D29/165especially adapted for liquid pumps F04D29/167of a centrifugal flow wheel F04D29/168of an axial flow wheel F04D29/18Rotors specially for elastic fluids F04D29/26 F04D29/181Axial flow rotors F04D29/185 take precedence F04D29/183Semi axial flow rotors F04D29/185Rotors consisting of a plurality of wheels F04D29/186Shaftless rotors F04D13/024 takes precedence F04D29/188specially for regenerative pumps F04D29/20Mounting rotors on shafts F04D29/22specially for centrifugal pumps F04D29/2205Conventional flow pattern F04D29/18 takes precedence F04D29/2211More than one set of flow passages F04D29/2216Shape, geometry F04D29/2211 takes precedence F04D29/2222Construction and assembly F04D29/2211 takes precedence F04D29/2227for special materials F04D29/2233entirely open or stamped from one sheet F04D29/2238Special flow patterns F04D11/005 takes precedence F04D29/2244Free vortex F04D29/225Channel wheels, e.g. one blade or one flow channel F04D29/2255flow-channels with a special cross-section contour, e.g. ejecting, throttling or diffusing effect F04D29/2261with special measures F04D29/2266for sealing or thrust balance F04D29/04 and F04D29/16 take precedence F04D29/2272for influencing flow or boundary layer F04D29/2277for increasing NPSH or dealing with liquids near boiling-point F04D29/2283for reverse pumping action F04D29/2288for comminuting, mixing or separating F04D29/2294for protection, e.g. against abrasion F04D29/24Vanes F04D29/242Geometry, shape F04D29/245for special effects F04D29/247elastic or self-adjusting F04D29/26Rotors specially for elastic fluids F04D29/263mounting fan or blower rotors on shafts F04D29/266mounting compressor rotors on shafts F04D29/28for centrifugal or helico-centrifugal pumps for radial-flow or helico-centrifugal pumps F04D29/281for fans or blowers F04D29/282the leading edge of each vane being substantially parallel to the rotation axis F04D29/283rotors of the squirrel-cage type F04D29/284for compressors F04D29/285the compressor wheel comprising a pair of rotatable bladed hub portions axially aligned and clamped together F04D29/286multi-stage rotors F04D29/287with adjusting means F04D29/288Part of the wheel having an ejecting effect, e.g. being bladeless diffuser F04D29/289having provision against erosion or for dust-separation F04D29/30Vanes F04D29/305Flexible vanes F04D29/32for axial flow pumps F04D29/321for axial flow compressors F04D29/322Blade mountings F04D29/323adjustable F04D29/324Blades F04D29/325for axial flow fans blade mountings F04D29/34, blades F04D29/38 F04D29/326comprising a rotating shroud F04D29/327with non identical blades F04D29/328with unequal distribution of blades around the hub F04D29/329Details of the hub F04D29/34Blade mountings for axial flow compressors F04D29/322 F04D29/36adjustable flexible blades F04D29/382 F04D29/362during rotation F04D29/364The blades having only a predetermined number of possible positions F04D29/366Adjustment by interaction of inertion and lift F04D29/368Adjustment by differences of temperature F04D29/38Blades for axial flow compressors F04D29/324 F04D29/382Flexible blades F04D29/384characterised by form F04D29/386Skewed blades F04D29/388characterised by construction F04D29/40CasingsConnections of working fluid bleed or by-pass valves F04D15/0011, F04D27/0215 F04D29/403especially adapted for elastic fluid pumps F04D29/406especially adapted for liquid pumps F04D29/42for radial or helico-centrifugal pumps F04D29/4206especially adapted for elastic fluid pumps F04D29/4213suction ports F04D29/422Discharge tongues F04D17/04 takes precedence F04D29/4226Fan casings F04D29/4233with volutes extending mainly in axial or radially inward direction F04D29/424Double entry casings F04D29/4246comprising more than one outlet F04D29/4253with axial entry and discharge F04D29/426especially adapted for liquid pumps F04D29/4266made of sheet metal F04D29/4273suction eyes F04D29/428Discharge tongues F04D17/04 takes precedence F04D29/4286inside lining, e.g. rubber F04D29/4293Details of fluid inlet or outlet F04D29/44Fluid-guiding means, e.g. diffusers F04D29/441especially adapted for elastic fluid pumps F04D29/442rotating diffusers F04D29/444Bladed diffusers F04D29/445especially adapted for liquid pumps F04D29/447rotating diffusers F04D29/448bladed diffusers F04D29/46adjustable F04D29/462especially adapted for elastic fluid pumps F04D29/464adjusting flow cross-section, otherwise than by using adjustable stator blades F04D29/466especially adapted for liquid fluid pumps F04D29/468adjusting flow cross-section, otherwise than by using adjustable stator blades F04D29/48for unidirectional fluid flow in reversible pumps rotors for reverse action F04D29/2283 F04D29/483especially adapted for elastic fluid pumps F04D29/486especially adapted for liquid pumps F04D29/50for reversing fluid flow rotors for reverse action F04D29/2283 F04D29/503especially adapted for elastic fluid pumps F04D29/506especially adapted for liquid pumps F04D29/52for axial pumps F04D29/522especially adapted for elastic fluid pumps F04D29/524shiftable members for obturating part of the flow path F04D29/526Details of the casing section radially opposing blade tips ducts F04D29/545 F04D29/528especially adapted for liquid pumps F04D29/54Fluid-guiding means, e.g. diffusers F04D29/541Specially adapted for elastic fluid pumps F04D29/56 takes precedence F04D29/542Bladed diffusers fixing blades to stators F01D9/042 F04D29/544Blade shapes F04D29/545Ducts F04D29/547having a special shape in order to influence fluid flow F04D29/548Specially adapted for liquid pumps F04D29/56 takes precedence F04D29/56adjustable F04D29/563specially adapted for elastic fluid pumps F04D29/566specially adapted for liquid pumps F04D29/58Cooling of machines or engines in general F01PHeatingDiminishing heat transfer for the motor of air-pump units F04D25/082; cooling of shafts or bearings F04D29/04 F04D29/5806Cooling the drive system F04D29/5813Cooling the control unit F04D29/582specially adapted for elastic fluid pumps F04D29/5826Cooling at least part of the working fluid in a heat exchanger F04D29/5833flow schemes and regulation thereto F04D29/584cooling or heating the machine F04D29/5846, F04D29/5853 take precedence F04D29/5846cooling by injection F04D29/5853heat insulation or conduction F04D29/586specially adapted for liquid pumps F04D29/5866Cooling at last part of the working fluid in a heat exchanger F04D29/5873flow schemes and regulation thereto F04D29/588cooling or heating the machine F04D29/5886, F04D29/5893 take precedence F04D29/5886cooling by injection F04D29/5893heat insulation or conduction F04D29/60MountingAssemblingDisassembling F04D13/10 takes precedence F04D29/601specially adapted for elastic fluid pumps F04D29/602Mounting in cavities F04D29/603means for positioning from outside F04D29/604means for removing without depressurising the cavity F04D29/605specially adapted for liquid pumps F04D29/606Mounting in cavities F04D29/607means for positioning from outside F04D29/608means for removing without depressurizing the cavity F04D29/62of radial or helico-centrifugal pumps F04D29/622Adjusting the clearances between rotary and stationary parts F04D29/624especially adapted for elastic fluid pumps F04D29/626Mounting or removal of fans F04D29/628especially adapted for liquid pumps F04D29/64of axial pumps F04D29/642by adjusting the clearances between rotary and stationary parts F04D29/644especially adapted for elastic fluid pumps F04D29/646Mounting or removal of fans F04D29/648especially adapted for liquid pumps F04D29/66Combating cavitation, whirls, noise, vibration or the like gas-flow silencers for machines or engines in general F01NBalancing surge control F04D27/02 F04D29/661especially adapted for elastic fluid pumps F04D29/662Balancing of rotors compensating unbalance G01M1/36 F04D29/663Sound attenuation F04D29/664by means of sound absorbing material F04D29/665by means of resonance chambers or interference F04D29/666by means of rotor construction or layout, e.g. unequal distribution of blades or vanes F04D29/667by influencing the flow pattern, e.g. suppression of turbulence F04D29/668damping or preventing mechanical vibrations F04D29/669especially adapted for liquid pumps F04D29/18 takes precedence F04D29/68by influencing boundary layers by bleeding elastic fluid F04D27/0215 F04D29/681especially adapted for elastic fluid pumps F04D29/682by fluid extraction F04D29/684by fluid injection F04D29/685Inducing localised fluid recirculation in the stator-rotor interface F04D29/687Plasma actuators therefore F04D29/688especially adapted for liquid pumps F04D29/70Suction gridsStrainersDust separationCleaning F04D29/701especially adapted for elastic fluid pumps F04D29/703specially for fans, e.g. fan guards F04D29/705Adding liquids F04D29/706Humidity separation F04D29/708specially for liquid pumps F04D31/00Other non-positive-displacement pumps F04D31/00Pumping liquids and elastic fluids at the same time F04D33/00Non-positive-displacement pumps with other than pure rotation, e.g. of oscillating type F04D35/00 takes precedence; hand-held fans A45B F04D35/00Pumps producing waves in liquids, i.e. wave-producers for bath tubs A47K3/10